Advanced magnetic resonance imaging in benign hereditary chorea: Study of two familial cases

No brain abnormalities are usually detected on conventional magnetic resonance imaging (MRI) in benign hereditary chorea (BHC); there are currently no studies with advanced techniques in literature. We investigated whether conventional and advanced MRI techniques could depict regional brain abnormalities in two familial BHC patients and 24 healthy controls. No brain abnormalities on conventional scans were detectable; also, no significant differences in fractional anisotropy of the basal nuclei were observed. Volumetric analysis showed a decreased volume of the striatum bilaterally compared with controls, whereas spectroscopy demonstrated a significant increased myoinositol/creatine ratio bilaterally, a reduction of choline/creatine ratio bilaterally, and of N‐acetyl‐aspartate/creatine in the right putamen. With the limits of the small sample size in the patient group, these data show that, despite the absence of macroscopic changes on conventional MRI, volumetric and metabolic abnormalities are present in the basal nuclei of BHC patients. © 2010 Movement Disorder Society.     

Single-photon emission computed tomography of the dopamine transporter in parkinsonism.

The known dopaminergic abnormalities in Parkinson's disease have facilitated the development of radiolabeled biomarkers for diagnostic and research applications in humans. Presynaptic, intrasynaptic, and postsynaptic imaging now is possible using single-photon emission computed tomography. In particular, the development of new radiotracers that target the dopamine transporter located on degenerating dopamine neurons in Parkinson's disease and related disorders is directly relevant to improved clinical diagnosis, disease monitoring, and assessment of putative neuroprotective strategies in patients. In addition, the ability to characterize in vivo neuronal degeneration in these disorders provides a powerful research tool to better understand the natural course of these disorders and could provide clues to etiology.     

Brain single-photon emission computed tomography and magnetic resonance imaging in Machado-Joseph disease

BACKGROUND: Machado-Joseph disease (MJD) is one of the most frequently encountered spinocerebellar ataxias. However, few reports on brain single-photon emission computed tomographic (SPECT) imaging (BSI) with hexylmethylpropylene amineoxine labled with technetium Tc 99m and magnetic resonance imaging (MRI) have been performed for the evaluation of patients with MJD. OBJECTIVES: To investigate possible abnormalities with BSI and MRI in patients with MJD and to correlate these findings with the duration of symptoms; cerebellar, extrapyramidal, and pyramidal syndromes; and the molecular characteristics of the MJD mutation. PATIENTS AND METHODS: Twelve patients (8 males and 4 females [mean age, 39 years]) with genetically proven MJD were studied. The patients underwent BSI and MRI on the same day. Brain SPECT imaging was performed after an intravenous injection of 99mTc-hexylmethylpropylene amineoxine. The transaxial, coronal, and sagittal BSIs obtained were submitted to visual and semiquantitative analyses. Magnetic resonance imaging was obtained in a 2-T system with coronal, sagittal, transaxial, and 3-dimensional (volumetric) acquisitions. The volumes of the cerebellar hemispheres and vermis were calculated. Control groups for BSI (22 female and 20 male subjects [mean age, 33 years]) and MRI (13 female and 4 male subjects [mean age, 32.2 years]) were included for comparison. RESULTS: Correlation was observed between the perfusion abnormalities identified by visual analysis in the BSI with the structural abnormalities observed on MRI in the parietal lobes and vermis. Brain SPECT imaging identified (by visual analysis) more perfusion abnormalities in the inferior portion of the frontal lobes, mesial and lateral portions of the temporal lobes, basal ganglia, and cerebellar hemispheres. Magnetic resonance imaging identified more abnormalities in the pons and superior portions of the frontal lobes. Olivary atrophy was identified by MRI. Semiquantitative analysis showed a statistically significant difference of perfusion in the inferior and superior portions of the frontal lobes, lateral portion of the temporal lobes, parietal lobes, left basal ganglia, cerebellar hemispheres, and vermis when compared with the control group. A significant difference was noted between the vermis and cerebellar volumes on MRI when compared with the control group. A significant relationship was observed between the perfusion of the left parietal lobe (P =.05) and extrapyramidal syndrome. There was a tendency toward an inverse relationship between the duration of symptoms and the perfusion of the cerebellar hemispheres (rho = -0.37; P =.24) and volume of the vermis (rho = -0.30; P =.34); between the length of the expanded (CAG)n repeat and the perfusion of the left parietal lobe (rho = -0.32; P =.36), vermis (rho = -0.28; P =.43), and pons (rho = -0.28; P =.42). A direct association was observed between the length of the expanded (CAG)n repeat and the perfusion of the lateral portion of the right temporal lobe (rho = 0.67; P =.03). CONCLUSIONS: Brain SPECT imaging and MRI were capable of identifying subclinical abnormalities in individuals with MJD. These findings may be helpful for a better understanding of the pathophysiology of this disease.     

健康老年人脑单光子发射计算机体层摄影术及磁共振显像的研究

目的研究健康老年人脑的功能性和结构性影像学特征。方法将73名年龄≥60岁的健康志愿者按年龄分为60～65岁组（第1组）、66～70岁组（第2组）和>70岁组（第3组）,采用单光子发射计算机体层摄影术对3组进行脑组织检查,并对其中的29名自愿者进行脑磁共振显像检查。结果（1）经方差分析,第2组和第3组脑组织几乎所有部位（除右丘脑和扣带回外）的灌注均低于第1组,其中第2组右顶叶灌注的放射性计数比值（RAR）为0.87±0.18,低于第1组（RAR=0.98±0.17;P<0.01）;（2）经配对t检验,除第2组的双侧顶叶外,3组颞叶和顶叶的灌注均为右侧高于左侧（P<0.01和0.05）;（3）经方差分析,第3组的灰质体积占颅内容积的百分比［（47.59±1.26）%］小于第2组［（49.43±1.30）%］,总脑脊液体积占颅内容积的百分比［（14.61±3.16）%］大于第1组［（12.41±0.73）%］和第2组［（11.94±1.27）%］,右侧海马体积［（2.04±0.23）cm     

Deep serotonergic and dopaminergic structures in fetal alcoholic syndrome: a study with nor-beta-CIT-single-photon emission computed tomography and magnetic resonance imaging volumetry.

BACKGROUND: In prenatally alcohol exposed children, the relationship between brain structure and function is highlighted to be important to study. METHODS: We studied 12 children with fetal alcoholic syndrome (FAS) and fetal alcoholic effects (FAE) by magnetic resonance imaging volumetry and by single-photon emission computed tomography with iodine-123 labeled 2beta-carbomethoxy-3beta-(4-iodophenyl) ([123I]nor-beta-CIT) and related these findings to those from neuropsychological and psychiatric tests. RESULTS: The absolute volumes of studied nuclei, including the brain volume, were significantly smaller in FAS/FAE children than in control patients. After normalization of volumes, significant differences were not found. Left hippocampus was smaller than the right (p<.003) but did not significantly differ from the control subjects. The children with FAS/FAE showed reduced serotonin (p=.02) in the medial frontal cortex and slightly increased striatal dopamine transporter binding. All FAS/FAE children had attention-deficit/hyperkinetic disorder (ADHD). None had depression. The internalization scores correlated with dopamine transporter binding (r=-.65; p=.03). CONCLUSIONS: The results indicate that the serotonin (5-HT) system may be vulnerable to the effects of ethanol in utero. The high dopamine transporter levels may correlate with the ADHD findings. Reduced serotonin and increased binding of dopamine transporter are also seen in type 2 alcoholism. Some behavioral problems of FAS/FAE might be preventable by early intervention and treatment.     

Treatment of Sydenham chorea with corticosteroids.

Despite treatment with valproic acid and neuroleptics, a significant proportion of patients with Sydenham chorea (SC) remain with chorea. We evaluated the effect of intravenous methyl-prednisolone followed by oral prednisone in patients with SC refractory to conventional treatment. Patients were enrolled in the study if they failed to improve with conventional treatment, despite the development of side effects. Chorea was rated on a 0 to 4 score. Five patients, 3 of them women, were included in the study. The median pretreatment rating score of the chorea was 3 (range, 3-4) and dropped to 1 (range, 0-2) after a median follow-up of 7 months (range, 3-7 months). Two patients developed Cushing syndrome. Our data suggest that intravenous methyl-prednisolone followed by oral prednisone is an effective and well-tolerated treatment of refractory SC.     

Magnetic resonance and positron emission tomography changes during the clinical progression of Rasmussen encephalitis.

The authors describe serial positron emission tomography (PET) and magnetic resonance imaging (MRI) studies in a patient with pathologically confirmed Rasmussen Encephalitis (RE). Results of initial PET and MRI studies were normal. Subsequent studies showed involvement of the percentral and postcentral gyri and the putamen on PET, and the precentral and postcentral gyri on MRI. Coregistration of PET and MR images showed good correlation between the precentral and postcentral gyri involvement. However, subcortical involvement occurred earlier on PET than on MRI. The authors demonstrate the evolution of changes on PET and MR images in a patient with RE. Despite early pathologic confirmation of RE, there were no definite structural or functional imaging changes on PET or MRI until 3 years after symptom onset. These findings demonstrate the variability of imaging changes in RE, and the need to carefully correlate electro-physiologic and clinical findings to confirm the diagnosis of RE.     

Diffusion-weighted magnetic resonance imaging in the syndrome of acute bilateral basal ganglia lesions in diabetic uremia.

In this report, we have presented a diabetic patient with uremia, in which acute Parkinsonism occurred, coupled with acute mental confusion, after a sudden increase in blood urea nitrogen and serum creatinin levels. Diffusion-weighted magnetic resonance imaging revealed a unique cytotoxic-type edema in the bilateral basal ganglia during the acute phase. Signal alterations were shown to regress in accordance with the normalized apparent diffusion coefficient (ADC) values, but irreversible cystic degeneration developed in the globus pallidus, with the very low preceding ADC values.     

Magnetic resonance imaging and computed tomography in Alzheimer's disease

Structural neuroimaging with CT and MRI plays an important role in the routine clinical investigation of dementia patients. One major purpouse of the technique is to exclude secondary, treatable dementia disorders. In this respect these techniques are of utmost importance. Another major purpose of these techniques is to differentiate AD from healthy controls and other dementias.
Although some research groups have reported a high sensitivity and specificity for diagnosing AD by measuring the volumes (with MRI) of structures in the temporal lobes, there are no unequivocal "radiological" markers (such as the size of the lateral ventricles or sulci) that can differentiate AD from controls or vascular dementia. There have been a large number of CT and MRI studies showing that the volumes of the temporal lobes or part of the temporal lobes, such as the hippocampal formation are reduced in AD, as compared to healthy subjects.
The role of white matter changes (WMH, leukoaraiosis) in the development of AD or as a diagnostic marker for AD is unclear. The degree of WMH has been shown to be strongly age dependent and there are contradictory data concerning its relation to cognitive decline. There is stronger agreement concerning the relationship between LA assessed with CT and cognitive functions than there is between WMH on MRI and cognitive functions.
Correlative studies with MRI, CT and SPECT or PET are few. Usually the sensitivity and specificity of diagnosing AD can be increased by combining two or more modalities. One other goal with this approach is to use one structural modality, such as MRI or CT as a template for functional images in order to obtain a higher accuracy in measurement of blood perfusion or glucose metabolism.     

Magnetic resonance imaging: significance of early ischemic changes on computed tomography

The significance of early ischemic changes (EICs) on CT remains controversial. MRI may provide relevant information in patients with EICs. METHODS: EICs were assessed in patients with acute ischemic stroke. MRI was promptly performed at presentation after CT and repeated on day 1. The relationship between EICs and MRI parameters was assessed with one-way ANOVA for analysis of continuous variables and by the chi2 test for the analysis of variables with a binary outcome. RESULTS: Fourty-eight patients underwent CT and MR imaging before treatment with recombinant tissue plasminogen activator (age: 63 +/- 14 years). EICs were graded as absent in 28 patients, <33% in 15 patients, and >33% of the middle cerebral artery (MCA) territory in 5 patients. NIHSS score was higher in patients with EICs that covered more than one third of the MCA territory (19 +/- 3) compared to those without EICs (12 +/- 5; p = 0.04). Patients who had major EICs had a larger acute lesion volume in diffusion-weighted imaging (DWI; 140 +/- 78 cm3) compared to those without EICs (33 +/- 51 cm3, p < 0.0001). Regional cerebral blood flow, regional cerebral blood volume, time to peak and mean transit time values were not significantly different in the study groups. CONCLUSION: EICs reflect mainly a larger DWI lesion.     

Clinical and positron emission tomography findings of chorea associated with primary antiphospholipid antibody syndrome.

A fourteen-year-old right-handed male with a history of attention deficit hyperactivity disorder (ADHD) presented with alternating hemichorea. Laboratory findings included elevated anticardiolipin IgG and anti-beta(2)-glycoprotein I IgG, which were consistent with primary antiphospholipid antibody syndrome. Positron emission tomography (PET) imaging revealed altered striatal metabolism in his left putamen while he was exhibiting right-sided hemichorea. His symptoms resolved on prednisone; however, his antiphospholipid antibody profile remained markedly abnormal despite being symptom-free for 26 months.     

Wilson's disease tremor is associated with magnetic resonance imaging lesions in basal ganglia structures.

Wilson's disease (WD) is an inherited disorder of copper metabolism yielding marked motor deficits, including a severely disabling tremor. As a structural correlate of the disease, a variety of cerebral abnormalities has been revealed. However, the relationship between motor deficits and cerebral lesions has remained largely unknown. Here, we investigated correlation between WD tremor and cerebral magnetic resonance imaging (MRI) findings. Cerebral MRI abnormalities in 6 symptomatic WD patients were compared to findings in 6 asymptomatic WD patients and 10 healthy controls. All patients were treated with long-term copper chelating therapy. Motor symptoms including tremor were determined by Unified Parkinson's Disease Rating Scale Part III (UPDRS-III). MRI findings in symptomatic WD patients revealed significant symmetric T2*-weighted hypointense signal alterations of globus pallidus, head of the caudate nucleus, and substantia nigra. In contrast, MRI of asymptomatic WD patients did not differ from healthy controls. Correlation analysis revealed a significant positive correlation between MRI basal ganglia lesions and UPDRS action tremor score. Our results demonstrate for the first time that Wilson's disease tremor is associated with lesions of the globus pallidus, the head of the caudate nucleus, and the substantia nigra.     

Striatal volume on magnetic resonance imaging and repetitive behaviors in autism.

BACKGROUND: The repetitive behaviors seen in autism phenotypically resemble those seen in obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), disorders in which structural and functional abnormalities of the basal ganglia (BG) are present and correspond to the severity of repetitive behaviors. METHODS: Seventeen subjects with autism by DSM-IV and Autism Diagnostic Interview (ADI) and 17 matched controls completed a 1.5 T magnetic resonance image (MRI) of the brain. Two blinded researchers, with good inter-rater reliability, outlined the right and left caudate and putamen. Autistic and control BG volumes covaried for total brain volume were compared using analysis of covariance. BG volumes within the autistic group were correlated with the ADI Repetitive Behavior scores (ADI-C domain). RESULTS: Right caudate volume controlled for total brain volume was significantly larger in autistic subjects than in controls. In addition, right caudate and total putamen volumes correlated positively with repetitive behavior scores on the ADI-C domain, particularly the higher order OCD-like repetitive behaviors. CONCLUSIONS: Increased right caudate volume in autism is of interest, since this has also been observed in OCD patients. Increased volume of the right caudate and total putamen positively correlated with greater repetitive behaviors, supporting the hypothesis of BG dysfunction associated with repetitive behaviors in autistic adults.     

Positron emission tomography and single-photon emission computed tomography in central nervous system drug development

In this review, the value of functional imaging [positron emission tomography (PET)/single-photon emission computed tomography (SPECT)] in drug development is considered. Radionuclide imaging can help establish the diagnosis of neurodegenerative disorders where this is in doubt and provides a potential biomarker for following drug effects on disease progression. PET and SPECT can help understand mechanisms of disease and determine the functional effects of therapeutic approaches on neurotransmission and metabolism. Synthesizing radiotracer analogs of novel drugs can provide proof of principle that these agents reach their enzyme or receptor targets and delineate their regional brain distribution. If such radiotracers do not prove to have ideal properties for imaging, the concept of microdosing potentially allows multiple other drug analogs to be tested with less stringent regulatory requirements than for novel medicinals. Finally, PET tracers can provide receptor and enzyme active site dose occupancy profiles, thereby guiding dosage selection for phase 1 and phase 2 trials. The eventual hope is that radiotracer imaging will provide a surrogate marker for drug efficacy, although this has yet to be realized, and progress the concept of personalized medicine where receptor/enzyme binding profiles help predict therapeutic outcome.     

孤独症患儿脑单光子发射计算机体层摄影术的研究

目的 研究孤独症患儿的脑血流和细胞功能.方法 采用单光子发射计算机体层摄影术,对31例符合中国精神疾病分类方案与诊断标准第2版修订本中孤独症的诊断标准的患儿(研究组)和20名排除神经精神科疾病、患躯体疾病的非孤独症儿童(对照组)进行脑影像分析.结果 (1)视觉定性分析,研究组中有27例存在36个放射性分布减低区,其中以左侧额叶(13个)和双侧颞叶(左右侧分别为6个和8个)皮质较多见.(2)放射性计数分析,研究组左侧额叶(84±34)和海马(62±23)低于右侧[分别为(88±32)和(67±26)],差异有非常显著性(P<0.01);对照组各部位左右侧比较,差异均无显著性.结论 孤独症儿童左侧额叶、海马及双侧颞叶存在局部血流灌注降低和细胞功能障碍.     

A study of computed tomography scan and magnetic resonance imaging findings in pseudohypoparathyroidism

We report three children with pseudohypoparathyroidism aged 13-16 years who presented with seizures and tetany. CT scan revealed striatopallidal calcification in two. MRI revealed wide-spread involvement showing T1 hyperintensity in striatopallidodentate distribution in all three and midbrain in one patient. T2 and FLAIR images were normal. T1 hyperintensity could represent early stage of calcification in whom MRI is more sensitive.